Fireplace heating system



r o t n e Z n n 3 4 Sheets-Sheet 1 NEW/*7 I Gflomeg June 23, 1953 N TBROWN FIREPLACE HEATING SYSTEM Flled May 20 1949 June 23, 1953 N. 1'.BROWN 2,642,359

' FIREPLACE HEATING SYSTEM Filed May 20, 1949 4 Sheets-sheaf. 2-

3noentor NEW/WIN 7'. Bzaow/v Ottomeg June 23, 1953 N. T. BROWN FIREPLACEHEATING SYSTEM 4 Sheets-Shebt 5 Filed May 20, 1949 Patented June 23,1953 FIREPLACE HEATING SYSTEM Newman T. Brown, Edmonds, Wash, assignorto Frank A. Mortimer, Seattle, Wash.

Application May 20, 1949, Serial N 0. 94,398

1 This invention relates to fireplace heating systems and has referencemore particularly to a fireplace heating system of an improved form; adevice that may readily be disposed within the combustion chamber of adomestic fireplace of the usual type of construction, or withinacirculating, air-heating fireplace, to convert the fireplace into acirculating heater.

It is'the principal object of this invention to provide a fireplaceheater of the above stated character, built as an integral unit and madeready for instant use merely by properly disposing it in the fireplacecombustion chamber of any make of fireplace or fireplace heating unit;that requires no change or alteration in the fireplace structure for itsapplication thereto and which may be easily withdrawn from use should itbe desired to use the fireplace or circulating airheating fireplace inthe usual way. Furthermore, to provide a circulating air heater for usewithin a fireplace, that takes advantage, to the maximum extent, of heatthat is contained in the smoke and gases of combustion and which usuallyis wasted through the fireplace chimney.

It is also an object of the invention to provide a heater of the abovestated character, having a firebox provided with a damper-equipped topfiue or outlet, permitting direct outflow of smoke and gases ofcombustion to the fireplace chimney and provided immediately about thesaid firebox with an enclosing housing providing anair heating chamberhaving air intake and discharge openings in direct communication withthe area or room to be heated; the said smoke and gas outlet of thefirebox being equipped with lateral outlets through which, upon closingthe damper, the smoke and hot gases will be diverted and caused to flowdownwardly and around the said air chamber to dissipate its heatthereto, thus providing means for causing smoke and gases of Icombustion to fiow over all sides of the air chamber both inside andout.

It is also an object of the present invention to provide a novelarrangement of baflies in association with the passages provided for theflow of smoke and hot gases, whereby the latter will be caused to bedistributed over the maximum area of those surfaces with-which the airthat is to be heated comes in contact.

Still further objects of the invention reside in the various details ofconstruction of parts embodied in the device and in their relationshipand mode of use as will hereinafter be fully described.

In accomplishing these andother objects of the invention, I haveprovided the improved de-- 2 Claims. (01.126-121) tails of construction,the preferredlforms of which are illustrated wherein:

Fig. 1 is a front view of a typical fireplace, equipped with acirculating air heater embodying the improvements of the presentinvention therein.

Fig. 2 is a somewhat enlarged vertical section in the accompanyingdrawings,

, of the fireplace and heater. as disposed therein;

the view being taken on the line 2-2 in Fig. 1. Fig. 3 is a perspectiveview of the present heater, removed from the fireplace and showingportions of walls of the various housings broken away for betterillustration and understanding of enclosed parts.

Fig. 4 is a transverse section of the air heater taken on the line 44 inFig. 2, with parts broken adjacent side wall of the outside housingremoved to show the baiiles that define the tortuous smoke passage atthat side of the firebox.

Fig. 6 is a horizontalsection taken on the line 66 in Fig. 2, showingthe heater in'plan view.

Fig. 7 is a horizontal section taken on the line 1-7 in Fig. 2. I

Fig. 8 is a sectional detail taken on the line 88 in Fig. 6, showing thedisposition of the side and auxiliary outlets of the smoke flue,relative to the top walls of the outside and inter- I mediate housings.

.Fig. 9 is an enlarged sectional detaihtaken on the line 9-9 in Fig. 1,illustrating the manner of use of an electric motor for creating forcedcirculation of air through the heater.

Fig. 10 is a vertical section of a heater of an alternative form.

Fig. 11 is a front elevation and partial crosssection of the same.

Described in a general way, the present air heater comprises a fireboxthat is open at the front to receive fuel and to permit view of theflame as the fuel burns, as is characteristic of the use of the usualfireplace. Immediately surrounding the firebox, except at the frontthereof, and spaced from the walls'thereof, is what is herein referredto as the intermediate housing. Likewise, immediately surrounding thesaid 'intermediate housing, except at the front thereof, and also spacedfrom the walls thereof, is what is herein referred to as the outsidehousing. The walls forming the firebox and those forming theintermediate housing are so spaced apart as to provide a chamberentirely about the firebox in which air will be heated by contact withthe enclosing walls; cool air being admitted to this chamber through anopening or openings thereinto located at the front and immediately belowthe firebox and the heated air being discharged into the area to beheated through an opening immediately above the firebox.

Between the walls of the outside housing and walls of the intermediatehousing and surrounding the latter, is a smoke chamber, equipped withbaffles so arranged as to provide tortuous passages through which thesmoke and gases from burning fuel may be diverted from direct flow tothe chimney to additionally heat the air chamber.

The present structure is of unitary character and is so designed that itmay be readily pushed into an open fireplace and thereby made ready forimmediate use, utilizing the chimney of the fireplace for thedisposition of smoke from its firebox, but not allowing heated air to bewasted out of the fireplace chimney.

Referring more in detail of the drawings:

In Figs. 1 and 2, I have illustrated a typical fireplace constructionwithin which a heater embodied by this invention is applied. It is shownbest in Fig. 2 that the fireplace comprises the usual form of combustionchamber I 0, which connects at the top with the chimney passage or fiueI I through a throat passage 12. The back of the combustion chamber It!comprises an upwardly and forwardly curved wall l3, terminating at thethroat passage [2, and across the front and top of the combustionchamber the brickwork is supported by horizontal lintel l4. The widthand height of the front opening into the fireplace combustion chamber isindicated in Fig. 1 in dotted lines at Him, and in Figs. 6 and '7 theopposite Side walls of the chamber ID are indicated at l5-l5 and areshown as being symmetrically inclined toward each other as they approachthe back wall IS.

The present circulating air heater is built in such dimensions that whenin place it substantially fills the combustion chamber of the fireplaceas will be understood by reference to Figs. 2, 6 and '7. The unit ispreferably constructed in its entirety of sheet metal of proper kind andgauge to meet requirements. In its preferred form of construction, itcomprises a firebox enclosing a combustion chamber IE. The firebox isformed with a horizontal bottom wall 18, a back wall [9, a top wall 20and opposite side walls 2I-2I .The sheet metal plates forming theseseveral walls are welded together, or otherwise so joined, as to givethe box the required strength, rigidity and air-tightness. The sidewalls 2 l-2l project somewhat below the opposite side edges of thebottom wall I8, thus to support the bottom wall above the floor surfaceof the fireplace and provide a passage immediately below wall 93 forentering air, and these side walls have their rear, lower cornerportions cut away, as at 22 in Figs. 2 and '7, to provide lateraloutlets for the flow of entering air from beneath the wall It to theopposite sides of the firebox as well as to the back thereof.

The back wall [9 of the firebox is upwardly and forwardly inclinedsubstantially in accordance with the inclination of the back wall of thefireplace, as noted in Fig. 2, and its opposite side walls, likewise,are set substantially parallel with the side walls l5--l5 of thefireplace, as noted in Fig. 6. The top wall 20 of the firebox isdownwardly and forwardly sloped, asseen in Fig. 2,

- control and adjustment of the damper.

for better retaining gases of combustion, and it has a downwardly andinwardly curved smoke guide 23 across its forward edge which also givesrigidity to this part of the structure.

Enclosing the unit is the outside housing, comprising a horizontal topwall 28, a back wall 29 and opposite side walls 3030. The back and sidewalls are set substantially parallel with the fireplace walls that areadjacent thereto, and preferably the walls of this outside housing areexteriorly covered with an insulating material such as sheet asbestos,indicated at 3|, to prevent outward dissipation of heat.

Disposed between the walls of the insulated outside housing and those ofthe inside firebox, is the intermediate housing. This housing, which isbest shown in Figs. 2, 3 and '7, comprises a horizontal top wall 34,opposite side walls 3535 and a back wall 36. These walls are parallelwith and spaced from the corresponding walls of the outside housing andfirebox and as associated with the latter they enclose the previouslymentioned air heating chamber that surrounds the firebox. As associatedwith the outside housing, the walls of the intermediate housing definethe inner walls of the smoke chamber that is immediately within thewalls of the outside housing.

At opposite sides and adjacent its top wall just back of the smoke guideflange 23, the firebox is equipped with outlets 38 leading through theair chamber and opening into the smoke chamber as shown best in Figs. 2,3 and 5. Also the firebox of the heater is equipped centrally, in thetop wall thereof, with a smoke outlet or fiue 40 that leads from thecombustion chamber l6, upwardly through the top walls 34 and 28 of theintermediate and outside housings and provides for a direct outflow ofsmoke to the fireplace chimney. This flue 40 is equipped at its upperend with a damper 4| that is fixed on a rotatably mounted rod 42 thatextends horizontally to the front of the fireplace, as shown in Figs. 2and 6, for the When the damper is open, smoke and gases may flowdirectly from the firebox to the chimney passage II, but when the damperis closed, as in Fig. 8, the smoke and gas will be caused to belaterally diverted through openings 43 that are provided in the oppositeside walls of the flue 40 and outlets 38 in the side walls of thefirebox, into the smoke chamber between the housing walls 28 and 34, andwill then be drawn laterally to opposite sides of the intermediatehousing, then downwardly, then to the back of the unit, and finallyupwardly to the fireplace flue, as presently will be fully described.

To fully understand the manner in which the heated air is controlled,and the means for the disposition of the smoke and gases from the unit,especially when the damper is closed, it is to be further explained thata flat metal plate 44 is applied vertically to the front of the unit asa closure member for the front of the fireplace combusion chamber, andto this plate the forward edges of the wall plates of the firebox, theintermediate housing and the outside housing are attached by welding orotherwise, as noted in Figs. 2 and 7. This front plate 44 has an opening44 registered with the front opening of the firebox, and has an opening45 across the bottom or lower edge for inflow of fresh or cool air tothe passage that is directly below the bottom wall of the firebox. Also,it has a horizontally directed opening 46 directly above the top wall ofthe firebox for outflow or discharge of heated air into the room that isbeing heated.

The plate 44 is of such dimensions that-it extends sufficiently beyondthe side and top walls of the outside housing to overlap with thefireplace walls about the entrance to the combustion chamber Hi; thisoverlap being shown-in Figs. 2, j

6 and 7, wherein it is shown also that a joint sealing material 41 isapplied about the edges of the plate, at the inside, to effectivelyretain smoke and gases, and also prevent air intake through this joint.

It is also to be explained that the back wall plate of the intermediatehousing extends from tight against the bottom surface of the fireplacechamber to the top Wall of the outside housing, as seen in Fig. 2, andthe side walls of the intermediate housing extend to the back wall ofthe outside housing, as seen in Fig. 6, except at their lower corners,which, as in Fig. 5, are cutaway to provide openings 48 for the fiow ofgases to the space between the back walls of the intermediate housingand outside housing.

Mounted between the side walls 38-30015 the outside housing and sidewalls -35 of the intermediate housing, in a manner as shown in Figs. 3and 5, are baffles 58 and 5|. The bafiles 58 extend from the rear uppercorners of the outside corners of the outside housing, downwardly andforwardly to the forward lower portions of the housing, then are turneddirectly downward, terminating somewhat above the lower edges of theside walls. The baffles 5| are spaced rearwardly from and below thebaffles 50 and extend vertically upward from the fioor of the fireplaceand have their upper end portions rearwardly inclined. The arrangementof bafiles 58 and 5|, at

each side of the heater, is like that at the other, and in each instancethey provide smoke passages at opposite sides of the intermediatehousing, which at their upper ends communicate with the open spacebetween the top walls 28 and 34, and at their lower ends communicate,about the lower ends of the bafiies 50, with passages that lead upwardlyand rearwardly, between the baffles 50 and 5|, then turn downwardly overthe upper ends of the baiiies 5| and connect through the side wallopenings 48 with passages that are formed between the rear walls of theintermediate housing and outside housing, these passages being shownbest in Fig. 4 and presently described.

It is shown in Figs. 2 and 3 that the top wall 28 of the outside housingis formed with an opening located in the top wall of the back fluecomprised by the smoke chamber space that is between the back walls ofthe outside and intermediate housings, and it provides for the outflowto the fireplace fiue of that smoke and gas that is diverted through theopenings 43 and 38 by, the closing of the damper in flue 48.

In order to spread the flow of smoke that enters through the openings 48over the back walls of the housings, for extraction of heat therefrom, Ihave extended the side walls 35-35 of the intermediate housing to theback wall of the outside housing, as shown in Fig. 5, and have placedbaiiies 58-58 and 59 between the walls 29 and 36 as shown in Fig. 4,wherein it is noted that the bafiles 58-58 are extended horizontallyfrom the opposite outer edges of the back wall 36, at the samehorizontal level a short distance above the fireplace floor, and arespaced at their inner ends to provide an open passage 68 between them.The baiiie 59 is disposed in a horizontal direction, at a distance abovebaffles 58-58, and has downwardly sloping opposite end portions thatterminate away from the side edges of the back wall to provide openpassages 6l-6l. Smoke that is drawn laterally from the flue 48 throughthe openings 43, and flows downwardly and through the tortuous passagesat the opposite sides of the intermediate housing, enters through thepassages 48, to the back side of the housing from opposite sides andbeneath the baflies 58-58,

' flows inwardly and upwardly through passage 68 then spreads laterallyand flows upward through the passages 6 l-6l and then out through thetop opening 55 to the fireplace flue or chimney.

It will be understood that by so diverting the flow of hot gas andsmoke, practically all heat therein will be dissipated to the housingwalls and will be extracted by the air that is to be heated anddischarged into the room through the front opening 46. Y

Assuming the device to be so constructed, and to be applied within afireplace as shown, or to be outside a fireplace and connected to a flueby a stovepipe, its mode of use would be as follows:

A fire is built'in the firebox chamber [6 in the usual manner, thedamper 4| being in its full open position. After a good fire has beenstarted and the chimney fiue has been sufiiciently heated to maintain agood upward draft, the damper may then be closed. This will cause thesmoke and hot gases of combustion to be diverted about the air heatingchamber by flow laterally across the top 34, and also under wall 28, anddown the opposite sides to the back and then upwardly to the chimneythrough opening 55. This will quickly and eifectively heat the airchamber both from inside and outside.

Air that enters the air chamber through the front opening 45 fiowsrearwardly and thence is distributed to the opposite sides and to theback of the firebox, flows upwardly and then across the top of thefirebox to the outlet 46 through which it is discharged to the area orroom to be heated.

I have shown also in Figs. 1 and 3 that there are openings -65 in thebottom edges of the front plate for admitting cool air into the spacesbetween the side walls of the firebox and intermediate housing. Theseopenings might ordinarily be closed, but are rovided for use in theevent that forced air circulation is desired. In event of use of theseopenings for forced air circulation, then the central opening 45 wouldbe covered by a plate 61 as has been shown in the sectional detail ofFig. 9, which illustrates the use of an electric motor and fan forcreating a forced flow of air.

It is shown in Fig. 7 that the wall 35 has a laterally offset portion35:: closing ofi the smoke passage and giving added space for thereception of the motor 68.and the fan 69 mounted on the motor shaft.

With the understanding that the openings 65-65 were uncovered, and thatopenin 45 was covered by the plate 61, it will then be understood thatoperation of the fans will draw in outside air and forcibly deliver itthrough opening 46.

When the forced air system is not being used, it is desirable that theopenings 65 be covered in order to prevent short circuiting of cool airdirect to the outlet 46.

In Figs. 10 and 11, I have illustrated an alternative constructionwhich, in addition to the features disclosed in the device as alreadydescribed, includes also an air chamber that entirely surrounds thesmoke chamber. In these views, part that correspond to parts alreadydescribed have been given the same reference numerals and thedescription pertaining thereto will not be repeated.

The alternative structure is characterized by the provision of an airspace or chamber that entirely surrounds the smoke chamber, so that heatthat is transmitted from the smoke to the outer wall of the smokechamber may be utilized. The housing which encloses this unit is formedwith a bottom wall 15, a back wall "at, top wall 71, and opposite sidewalls 'i,8l8. These various walls coaot respectively with the walls 18,29, 28, 30 and 30, to provide the air spaces and passages that surroundthe smoke chamber. It is shown in Fig. that the air that is to be heatedenters the heater at the front through opening 45, flows rearwardlybeneath the bottom l8 of the firebox, and then upwardly through the twofiues 80 and BI provided at the rear of the firebox, and also upwardlythrough the two flues $2 and 83 at each side of'the firebox, thenforwardly through the two passages 84 and 85 to the front opening 46. Itis shown in Fig. 10 that the passage 84 is connected with the outlet 46by a passage 88.

In this device, I have illustrated the device as being equipped with asliding damper Ala; in lieu of the pivoted damper, and it is adapted tobe shifted to and from closed position by means of a rod the thatextends to the front of the unit.

I have also shown the device as being equipped for forced aircirculation. To accomplish this, an electric air blower 90 is shown asbeing located within the front opening 45' to draw in air and toforcibly deliver it toward the rear of the unit. Bafiles to effect aproper distribution of air could be employed as required. Preferably theblower would be located centrally between opposite side walls and nearthe front and the opening 45' would be of limited size.

Devices of this character have proven to be exceptionally efilcient andeconomical. They may be made in various sizes to adapt them for use insmall or large fireplaces and may be changed in proportionate dimensionswithout departing from the spirit of the invention.

Heaters of this kind are especially useful for quick heating, forexample, in cool summer evenings, when it is not practical or desirablethat the housing heating plant be operated.

While I have not so illustrated it, it is to be understood that thepresent unit might be used as an ordinary heating stove by connecting itwith a chimney or flue by means of a stove pipe leading from the outlet55.

Having thus described my invention, what I claim as new therein anddesire to secure by Letters Patent is:

l. A unitary, portable, circulating air heater, adapted to be disposedwithin a fireplace combustion chamber and to close the front thereof,said heater comprising a firebox that is open to the front of thefireplace, an air heating chamber immediately surrounding the fireboxexcept at the front thereof, and. having an air inlet into the lowerportion of the chamber below the firebox and having an air outlet fromthe upper portion thereof above the firebox, the air inlet beingenclosed along opposite sides to conduct incoming air below the fireboxto near the back of the chamber for upflow at sides and back thereof,thence to be discharged through the air outlet, a smoke chamberenclosing the back, sides and top walls of the air heating chamber, anda top opening from the smoke chamber into the fireplace combustionchamber for flow of smoke to the fireplace flue, a flue for the fireboxproviding direct outflow of smoke and gases to the fireplace flue andhaving lateral outlets into the smoke chamber, a damper for the fireboxflue adjustable to an open position for direct flow of smoke to thefireplace flue, and adjustable to a closed position for diverting smokeand gases to the fireplace flue through said smoke chamber, bafilesdisposed in the smoke chamber to direct the circulation of smoke andgases therethrough downwardly at the sides of the firebox and to theback thereof, and bafiles on the back wall of the smoke chamber being sodisposed as to cause the smoke and gases that enter from opposite sidesat the bottom to flow upward through a central opening, thence to bediverted toward the opposite sides and subsequently to the outlet of thesmoke chamber.

2. A heater of the character described comprising an open front firebox,an air heating chamber immediately surrounding the firebox at all sidesexcept the open front, a smoke chamber immediately surrounding the airheating chamber, means for admitting cold air into the said air heatingchambers below the firebox, means for outflow of air from the airheating chamber above the firebox, a flue from the top of the fireboxfor direct outflow oi smoke and gases, and having lateral openings intothe smoke chamber, a smoke outlet for the smoke chamber and a damper forthe flue adjustable to open position for permitting direct outflow ofsmoke and gases and to closed position for diverting flow through thesaid lateral outlets to the smoke chamber; said smoke chamber havingbaflles disposed therein to direct the circulation of smoke and gasestherethrough downwardly at the sides of the firebox and to the backthereof, and baffles on the back wall of the smoke chamber being sodisposed as to cause the smoke and gases that enter from the oppositesides at the bottom to flow upward through a central opening, thence tobe diverted toward the opposite sides and sub sequently to the outlet ofthe smoke chamber.

NEWMAN T. BROWN.

References Cited in the flle of this patent UNITED STATES PATENTS NumberName Date 708,563 Krauter Sept. 9, 1902 1,287,815 Anderson Dec. 17, 19181,387,252 Gage Jan. 8, 1935 2,131,763 Sroat Oct. i, 1938 2,231,178Dollinger Oct. 5, 1943 2,360,611 Leonard Oct. 17, 194-4 FOREIGN PATENTSNumber Country Date 255,342 Switzerland Jan. 17, 1949

